Now all we need is someway to loot quest items and pass them to the other characters

Personally I wouldn't destroy greys unless they truely are worthless greys, otherwise your throwing good coin away. But if you need an addon to destroy/sell them theres's always www.lootfilter.com. My biggest problem with looting all with my main is limited bag space - after a while I have no choice but to start looting with my other characters.